Drive apparatus for converting linear motion to rotary motion

ABSTRACT

A drive apparatus and method for continuously transmitting power to an axle, shaft and the like are disclosed. The drive apparatus includes a flexible ratch (414) such as flexible chain, belt or cable and cooperating first and second ratch engaging energy transmitting members (434) for releasably engaging the flexible ratch (414) to continuously drive an axle (410), shaft or the like. To operate the apparatus, the first and second enerergy transmitting ratch engaging members (434) are moved in a direction parallel to the linear paths of the flexible ratch means (414) which causes the first ratch engaging member (434) to engage and drive the flexible ratch (414) which rotatingly drives the axle (410). The ratch engaging members (434) direction of movement is then reversed so that the first ratch engaging means (434) releases the flexible ratch means (414) as the second ratch engaging means (434) engages the flexible ratch means (414) to continuously drive the axle, shaft or the like (410).

TECHNICAL FIELD

The invention relates generally to method and apparatus for drivingaxles driven by chains, belts, cables and the like and, morespecifically, to a method and apparatus for driving wheelchairs,bicycles and motor vehicles powered by internal combustion engines.

BACKGROUND OF THE INVENTION

The prior art is replete with apparatus for driving wheel chairs andbicycles. Examples of such apparatus are disclosed in U.S. Pat. Nos.4,865,344; 4,762,332; 4,652,026; 4,453,729; 4,274,651; 4,063,747;3,994,509; 3,877,725; 3,666,292; 3,309,110; 1,273,693 and 494,839.

A review of the above patents reveals that none of the apparatusdisclosed therein is capable of receiving or transmitting linearlygenerated power, i.e. power which is generated by power strokestraveling along a straight line or path. All apparatus disclosed in thepatents require that the operator move a handle or pedal through somesort of an arcuate or curved path in order to make a power stroke with adevice. For example, in U.S. Pat. No. 3,877,725 to Barroza, it can beseen in FIG. 4 that the wheelchair is driven by moving handle 3 throughthe arcuate path illustrated by the arrows in FIG. 4. Similarly, in U.S.Pat. No. 4,063,747 to Young, it can be seen in FIG. 1 that the bicycledisclosed therein is powered by moving pedals 36 through an arcuatepath. It will also be appreciated that the pedal of a conventionalbicycle also follows an arcuate path as it revolves about the axis ofthe bicycle's main sprocket.

One problem with generating power along a curved or arcuate path is thatthe portion of the path over which maximum power can be generated isvery short. For example, in a conventional bicycle, maximum power isgenerated during that portion of the pedal's path which travels fromabout +45° from the horizontal to about -30° from the horizontal. As canbe visualized, it is difficult to generate significant power outsidethis portion of the pedal's path since the operator's foot is simply notat an angle with respect to the pedal which enables the generation ofmuch power. The connecting rod/crankshaft attached to the piston of aninternal combustion engine suffers from the same problem since themechanics of the combination are no different than that provided by thebicyclist leg/pedal combination.

DISCLOSURE OF THE INVENTION

The present invention addresses the aforementioned problems by providingmethod and apparatus for continuously transmitting linearly generatedpower to an axle and the like to rotatingly drive the axle. Theinvention theoretically maximizes the amount of power that can begenerated by an individual with an arm or leg since power generationtheoretically can be maximized if the arm or leg moves linearly, i.e.along a straight line during a stroke of the arm or leg for generatingpower. As such, the power transmitting or drive apparatus of the presentinvention is ideally suited for use with apparatus that are powered byan individual with his arms or legs. Some examples of suitable apparatusare bicycles and wheelchairs.

It has also been determined that the drive apparatus and method of thepresent invention more efficiently transmits the power of a linearpiston stroke to rotary motion and, as such, is ideally suited for usein an internal combustion engine.

In its broadest sense, the power transmitting or drive apparatus of thepresent invention includes flexible ratch means such as flexible chain,belt or cable and cooperating first and second power receiving ratchengaging members for releasably engaging the flexible ratch means tocontinuously drive a sprocket/pulley-type member which, in turn,continuously drives, i.e. rotates an axle or shaft which is axiallyaligned and connected to the sprocket/pulley type member. The axle couldbe the axle or driveshaft of a wheelchair, bicycle or motor vehicle andthe like which, when driven, would propel the wheelchair, bicycle ormotor vehicle.

In a preferred embodiment of the invention handle/pedal means, i.e.handles or pedals are also provided which are attached to thecooperating first and second ratch engaging members. This enables theapparatus to be powered by an individual with his arms or legs. Anotherpreferred embodiment of the invention utilizes the stroke of a uniquedual-headed piston which is attached to the cooperating first and secondpower receiving ratch engaging members to drive the driveshaft of amotor vehicle. This embodiment of the invention can also be used inreverse as a pump wherein the shaft of axle could be the shaft of anelectric motor which drives the drive apparatus in the oppositedirection thereby converting rotary motion to linear motion. Thisreverse operation of the drive apparatus would drive the dual-headedpiston in a reciprocating manner in its cylindrical chamber and, assuch, can be used to pump fluid through the cylindrical chamber.

The method of the present invention provides continuous driving of anaxle or shaft which may be that of a bicycle, wheelchair, motor vehicleor any other similar device. The method includes the steps of providinga drive apparatus as described above. The method further includes thestep of moving or powering the first and second ratch engaging powerreceiving members of the above-described apparatus in a directionparallel to the direction in which the flexible ratch is capable ofmoving so that the first ratch engaging member engages and drives theflexible ratch which rotates the sprocket/pulley-type member which, inturn, drives the axle. The method further includes a step of reversingthe first and second ratch engaging members' direction of movement sothat the first ratch engaging member releases the flexible ratch and thesecond ratch engaging member engages the flexible ratch. This releasingand engagement of the flexible ratch occurs simultaneously so thatrotation of the sprocket/pulley-type member continues uninterrupted,thereby continuously driving the axle or shaft.

BRIEF DESCRIPTION OF DRAWINGS

The invention will be more readily understood by reference to theaccompanying drawings wherein like reference numerals indicate likeelements throughout the drawing figures, and in which:

FIG. 1 is a perspective view of a wheelchair equipped with a driveapparatus of the present invention.

FIG. 2 is side elevation view of the drive apparatus for the wheelchairillustrated in FIG. 1.

FIG. 3 is an enlarged side elevational view of the chain engaging meansof FIG. 2 which illustrates the chain engaging members' position whenwheelchair occupant is making an upstroke with the wheelchair's forwardhandles.

FIG. 4 is in enlarged side elevation view similar to that illustrated inFIG. 3 showing, however, the chain engaging members in their neutralposition where they are disengaged from the drive chain.

FIG. 5 is a side elevation view similar to FIG. 3 showing, however, thechain engaging members in the position they assume when the wheelchairoccupant makes a downstroke with the wheelchair's forward handle.

FIG. 6 is a perspective view of a chain engaging member illustrated inFIGS. 2 through 5.

FIG. 7 is a side elevation view of a bicycle equipped with a driveapparatus of the present invention.

FIG. 8 is an enlarged side elevation view of the bicycle's driveapparatus FIG. 7.

FIG. 9 is a front elevation view of the bicycle's drive apparatus takenalong lines 9--9 of FIG. 7.

FIG. 10 is a perspective view of a second wheelchair embodiment of thepresent invention.

FIG. 11 is a side elevation view of the wheelchair of FIG. 10.

FIG. 12 is a partial front elevation view of the wheelchair of FIG. 10.

FIG. 13 is a cross-sectional view taken along lines 13--13 of FIG. 12.

FIG. 14 is a partial side elevational view of the wheelchairs FIG. 11.

FIG. 15 is a cross-sectional view taken along lines 15--15 of FIG. 14.

FIG. 16 is a cross-sectional view taken along lines 16--16 of FIG. 14.

FIG. 17 is a cross-sectional view taken along lines 17--17 of FIG. 14.

FIG. 18 is a cross-sectional view taken along lines 18--18 of FIG. 17.

FIG. 19 is a cross-sectional view taken along lines 19--19 of FIG. 17.

FIG. 20 partial cross-sectional view similar to FIG. 13 showing chainlink segment 242 engaging the drive chain of the apparatus.

FIG. 21 is a partial cross-sectional view similar to FIG. 20 showing thechain link segments in their neutral position.

FIG. 22 is a side elevational view of a second bicycle embodiment of thepresent invention.

FIG. 23 is a partial side elevational view of the drive apparatus of thebicycle illustrated in FIG. 22.

FIG. 24 is a cross-sectional view taken along lines 24--24 of FIG. 23.

FIG. 25 is a cross-sectional view taken along lines 25--25 of FIG. 24.

FIG. 26 is a perspective view of the drive apparatus of bicycle 300illustrated in FIGS. 22 and 23.

FIG. 27 is a side cross-sectional view of another embodiment of thepresent invention for driving the drive shaft of a motor vehicle.

FIG. 28 is a cross-sectional view similar to that of FIG. 27 showing,however, the dual-headed piston arrangement of this embodiment at theend of its upstroke.

FIG. 29 is a cross-sectional view taken along lines 29--29 of FIG. 27.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS. 1 through 6 illustrate an apparatus of the present invention fordriving a wheelchair 10 having a pair of propulsion wheels 12 which areattached to the frame of wheelchair 10. The apparatus includes a firstdrive sprocket 14 for driving the propulsion wheel which is attached toand axially aligned therewith by an axle 16. It will be appreciated thatanother drive apparatus (not illustrated) is located on the other sideof the wheelchair which is identical to the illustrated drive apparatus.

The drive apparatus of the present invention also includes a seconddrive sprocket 18 and a first drive chain 20 which is slung about thepair of first and second drive sprockets 14, 18.

The drive apparatus further includes a third drive sprocket 22 which isaxially aligned and rigidly attached to second drive sprocket 18. Afourth drive sprocket 24 is also provided as well as a second drivechain 26 which is slung about the pair of third and fourth drivessprockets 22, 24.

The apparatus further includes a first handle 28 which is rigidlyattached at point 30 to an endless cable 32 (slung about three pulleys38, 39, and 40) which is in turn connected to a chain engaging means 34at point 36. Chain engaging means 34 releasably engages chain 26 as awheelchair occupant makes upward and downward strokes with handle 28along a guide path 37 to continuously drive chain 26 in a clockwisedirection (as viewed from FIG. 2) which, in turn, continuously driveschain 20 to propel the wheelchair in a forward direction. (i.e. when thewheelchair occupant makes similar upward and downward strokes with thehandle 28 of the other drive apparatus located on the other side of thewheelchair). The details of chain engaging means 34 releasableengagement of chain 26 which drives the chain continuously in onedirection is described in more detail below.

FIG. 2 also illustrates that the drive apparatus of the presentinvention is provided with another handle 42 which is rigidly attachedto a pair of endless cables 44 and 46 at points 48 and 50, respectively.Cable 44 is attached to a pair of first and second chain engagingmembers 52 via a right pair of cable segments 54 and a left pair ofcable segments 56. Similarly, cable 46 is connected to another pair ofchain engaging members 58 via a right pair of cable segments 60 and aleft pair of cable segments 62. By attaching handle 42 to chain engagingmeans 34 in this fashion, chain 26 can be driven in the oppositedirection which propels the wheelchair in reverse when the wheelchairoccupant makes upward and downward strokes with handles 42. The detailsof how this is accomplished by the apparatus is described in detailbelow.

As with cable 32, cable 44 is also slung about three pulleys 64, 66 andpreviously mentioned pulley 40. Pulley 40 is provided with a separategroove (not shown) for guiding cable 44. Similarly, cable 46 is slungabout three pulleys 68, 70 and pulley 40 which is provided with yetanother groove (not shown) for guiding cable 46.

FIG. 2 also illustrates that the drive apparatus of the presentinvention includes a ball bearing track slider or sliding means 72 whichis slidably received in a track 74. Track 74 is mounted about the axles75,76 for sprockets 18 and 24. Track slider 72 is rigidly attached tothe central area of the underside surface of chain engaging means 34. Assuch, it will be appreciated that chain engaging means 34 can only movein a linear direction back and forth between the axles of sprockets 18and 24. This keeps chain engaging means 34 aligned with drive chain 26which is slung about sprockets 18 and 24.

FIG. 3 illustrates the details of chain engaging means 34 for drivingchain 26. As illustrated, chain engaging means 34 has a base 80 uponwhich are mounted pivoting chain engaging members 52(a),(b) and 58(a),(b). FIG. 6 illustrates a perspective view of chain engaging member52(a) which is identical to chain engaging members 52(b) and 58(a) and(b). As illustrated, each chain engaging member has an end 82 forhousing a bolt 84 which extends therethrough and which is used topivotally attach each chain engaging member to base 80. Each chainengaging member also has a free end 86 for swinging into engagement withthe concave edges 88 of chain 26. It will be appreciated that when thefree ends 86 of a chain engaging member are engaging a link of chain 26,chain 26 can be driven in either a forward or reversed direction. Thedirection of travel will depend upon which handle the wheelchairoccupant is grasping to make downstrokes and upstrokes with. Aspreviously mentioned, upstrokes and downstrokes made with handles 28propel the wheelchair in a forward direction while such made withhandles 42 propel the wheelchair in reverse.

FIG. 3 illustrates the position which chain engaging members 52 and 58are in when the wheelchair occupant makes an upstroke along guide path37. As can be visualized, when making an upstroke with handle 28, cable32 attached to handle 28 pulls base 80 to the right. When this happens,the inertia of cables 44 and 46 (which are rigidly attached to the freeends 86 of the chain engaging members 52, 58 via cable segments 54, 56,60 and 62) causes the free ends 86 of chain engaging members 52(a) and(b) to simultaneously engage a link of chain 26, i.e. engage the concaveedges 88 of a chain link of chain 26. While this is happening, theinertia of cable 46 causes the free ends 86 of chain engaging members58(a) and (b) to swing out of engagement with chain 26. Thus, it will beappreciated that with only the upper set of chain engaging members 52(a) and (b) engaging chain 26, chain 26 is driven in a clockwisedirection, which in turn propels the wheelchair forward (i.e., if asimilar stroke is made with the other handle 28).

When the wheelchair occupant finishes making upstrokes with handles 28and begins making downstrokes therewith, the chain engaging memberspivot from their positions illustrated in FIG. 3 to their positionsillustrated in FIG. 5. This pivoting occurs because base 80 is nowmoving to the left which causes the inertia of cable 44 to swing thefree ends 86 of chain engaging members 52(a) and (b) out of engagementwith chain 26. As this is happening, the inertia of cable 46 causes thefree ends 86 of chain engaging members 58(a) and (b) to swing intoengagement with chain 26. As such, those skilled in the art willappreciate that the movement or driving of chain 26 continues in theclockwise direction, thereby continuing the wheelchair's propulsion inthe forward direction.

The path traveled by the inertial forces generated by cables 44 and 46is somewhat difficult to explain, but is believed to be as follows. Whenmaking an upstroke with handle 28, the inertia of cable 44 istransmitted to free ends 86 of chain engaging members 58(a) and (b) viacable segments 56. Similarly, the inertia of cable 46 is transmitted tothe free ends 86 of chain engaging members 58(a) and (b) via cablesegments 62. When making a downstroke with handle 28, the inertialforces generated by cable 44 are transmitted to free ends 86 of chainengaging means 52(a) and (b) via cable segments 54. Similarly, theinertial forces generated by cable 46 are transmitted to the free ends86 of chain engaging members 58(a) and (b) via cable segments 60.

It is also important that the cable segments of each pair have the samelength. This insures that the chain engaging members to which the cablesegments are attached pivot simultaneously to simultaneously engage theoppositely facing concave edges 88 of a single chain link. Suchsimultaneous engagement of a chain link by a pair of chain engagingmembers is necessary in accordance with the present invention foreffective driving (and grabbing if you will) of the chain.

FIG. 4 illustrates chain engaging members 52(a) and (b) and 58(a) and(b) in a neutral position wherein neither set of chain engaging members52, 58 is engaging chain 26. The chain engaging members pivot into thisposition when the wheelchair occupant lets go of handles 28, 42 (or atleast stops making upstrokes with either pair of handles) and when thewheelchair moves forward, i.e., is either pushed or is coasting.

The chain engaging members pivot into neutral when the aforementionedhappens because the inertia of chain 26 pushes the chain engagingmembers out of engagement with the chain. This is to be contrasted withthe inertia of cables 44 and 46 which causes the free ends to move intoengagement with chain 26 when downstrokes and upstrokes are made withhandles 28 to propel the wheelchair forward.

The chain engaging members will remain in neutral (i.e., once put intoneutral) until the wheelchair occupant begins making either an upstrokeor downstroke with handles 28, 42. Once in neutral, the wheelchair canbe pushed, or, if desired, it can coast in either a forward or a reversedirection.

If the wheelchair were to accidentally begin coasting in reverse, thewheelchair occupant can stop such movement by grabbing either pair ofhandles 28, 42 and beginning to make an upstroke or downstroketherewith, as previously mentioned. This will move the chain engagingmembers into engagement-with the chain in one of the positionsillustrated in either FIGS. 3 or 5 (the particular position depending onwhich pair of handles is grabbed and whether an upstroke or downstrokeis made therewith) and the wheelchair will stop coasting in reverse whenhandles 28, 42 travel to the end of path 37. The wheelchair is preventedfrom coasting any further in reverse since the chain engaging membersstay engaged with chain 26 once they pivot into engagement therewith,even if the wheelchair occupant lets go of the handles. Those skilled inthe art will appreciate that the ability to prevent reverse coasting ofthe wheelchair is particularly desirable since it enables the wheelchairoccupant to stop the wheelchair on the hill and perform any desired taskwith his hands which the occupant is free to use since they do not haveto be used in any manner to prevent the wheelchair from coastingdownhill i.e. they do not have to be used to grab handles 28,42 or tosqueeze the wheelchair's hand brakes.

The chain engaging members can also be used to stop the wheelchair fromcoasting downhill in a forward direction. However, the process issomewhat different. Only the reverse pair of handles can be used and toprevent the wheelchair from beginning to coast forward again, theoccupant must keep the chain engaging members engaged with the chain byholding onto the reverse handles and applying enough pushing or pullingpressure to keep the chain engaging members engaged with the chain. Ifthe wheelchair occupant were to let go of the handles, the chainengaging members would simply pivot into neutral as previously describedwhen the wheelchair begins to coast forward. It should also be mentionedthat if the wheelchair is coasting downhill at a high rate of speed, thechain engaging members will not instantly engage the chain when handles42 are grabbed and pulled or pushed. They will, however, impact upagainst the chain and generate resistance to the chain's continuedmovement. In time, the chain will slow down and ultimately stop. Thismethod of braking the wheelchair is not the recommended method eventhough it works. The preferred braking method involves equipping thewheelchair with conventional hand brakes which, when squeezed, willbrake the wheelchair in the conventional manner.

FIG. 3 also illustrates the position to which chain engaging memberspivot when a wheelchair occupant makes a downstroke with reverse handle42, which drives the wheelchair in reverse. It will be appreciated,however, that it is not the inertia of cables 44, 46 which swing thechain engaging members into and out of engagement with chain 26 whenreverse handles 42 are used. Instead, it is the inertia of base 80. Itwill be recalled that reverse handle 42 is rigidly attached to bothcables 44 and 46. Accordingly, when the wheelchair occupant makes adownstroke with handle 42, cables 44 and 46 are pulled to the left, assuch is viewed from the perspective of FIGS. 2-5. Thus, it will beappreciated that it is the inertia of base 80 which acts on the freeends 86 of chain engaging members 52(a) and (b) to swing them intoengagement with chain 26. Similarly, it is the inertia of base 80 whichcauses the free ends 86 of chain engaging members 58(a) and (b) to swingout of engagement with chain 26.

The path taken by the inertial forces in swinging the chain engagingmembers into and out of engagement with chain 26 is as follows. Whenmaking a downstroke with reverse handle 42, the inertial forcesgenerated by base 80 are transmitted from base 80 through chain engagingmembers 58(a) and (b) through the free ends 86 thereof, and then throughcable segments 62 to cable 46, thereby causing chain engaging members58(a) and (b) to swing out of engagement with chain 26. Similarly, whenmaking downstroke with reverse handle 42, the bases's inertial forcesare transmitted from base 80 through chain engaging members 52, throughtheir free ends 86, and then through cable segments 56 which direct thefree ends into engagement with chain 26.

FIG. 5 illustrates the position to which chain engaging members 52 and58 pivot when the wheelchair occupant begins making an upstroke withreverse handle 42. It will be appreciated that when making an upstrokewith handle 42, cables 44 and 46 are pulled to the right. Thus, theinertia of base 80 pulls the free ends 86 of chain engaging members52(a) and (b) out of engagement with chain 26. The path of inertiatransmission is from base 80 through chain engaging members 52(a) and(b), through their free ends 86 and then through cable segments 54 tocable 44. Another way of perhaps explaining the movement of free ends 86out of engagement with chain 26 would be to state that the inertia ofbase 80 tensions chain engaging members 52(a) and (b) and cable segments54, thereby pulling the free ends of chain engaging members 52(a) and(b) out of engagement with chain 26.

With respect to chain engaging members 58(a) and (b) when making anupstroke with reverse handle 42, it will be appreciated that again, itis the inertia of base 80 which causes the free ends 86 of chainengaging members 58 (a) and (b) to move into engagement with chain 26.The inertial forces of base 80 travel through chain engaging members 58(a) and (b), through free ends 86 thereof and then through cablesegments 60 which direct free ends 86 into engagement with chain 26.

In view of the above, it will be appreciated that while the transmissionof the inertial forces may be difficult to understand, the abovedescribed apparatus enables chain 26 to be continuously driven-in acounterclockwise direction when viewed from the perspective of thedrawings, which in turn enables the wheelchair to be propelled inreverse.

FIGS. 7 through 9 illustrates another drive apparatus of the presentinvention which is fundamentally the same as that illustrated forwheelchair 10. However, this drive apparatus has been adapted to drivethe illustrated bicycle 100.

To make it easier for one to quickly understand the bicycle's driveapparatus, the components of the bicycle's drive apparatus which arefunctionally equivalent to those of the wheelchair's apparatus arenumbered similarly with the exception that the numbers are primed.

The major difference between the drive apparatus of bicycle 100 andwheelchair 10 is that the bicycle's drive apparatus has no means fordriving the bicycle in reverse. Reverse operation of bicycle 100 is,quite obviously, not necessary since bicycles are typically only drivenin a forward direction. Accordingly, those having an understanding ofthe wheelchair's drive apparatus will appreciate that there are nohandles or pedal means attached to cables 44' and 46' for drivingbicycle 100 in the reverse direction. Nonetheless, cables 44' and 46'are very important elements of the bicycle's drive apparatus since theyprovide the inertia for swinging the chain engaging members into and outof engagement with drive chain 26', which occurs in a manner identicalto that described for the wheelchair's drive apparatus as illustrated inFIGS. 3 through 5.

The other major difference between the drive apparatus for bicycle 100and wheelchair 10 is that cable 32' has a pair of left and right pedals,110 and 112, rigidly attached to it instead of the single handle 28provided in the wheelchair's drive apparatus. Those skilled in the artwill appreciate that the upstroke function provided by handle 28 in thewheelchair's drive apparatus is provided in the bicycle's driveapparatus by pedalling downwardly with pedal 112. Accordingly, it willbe appreciated that chain 26' can be continuously driven by pedallingthe bicycle in a conventional fashion. The only difference is that withthe drive apparatus of the present invention, a bicyclist will be ableto generate more power with greater efficiency since the strokes of eachpedal follow a straight line i.e. a linear path. As previously alludedto, a linear stroke is advantageous since it enables the bicyclist toexert more force on a pedal during a pedaling stroke than is possiblewith the pedal of a conventional bicycle which travels through anarc-like path.

Other differences between the wheelchair's drive apparatus and thebicycle's drive apparatus include the following:

1. Cable 32' is slung about a set of four pulleys 120 instead of thethree pulleys 38, 39 and 40 illustrated in FIG. 2. Those skilled in theart will appreciate that the set of four pulleys 120 could be replacedby a set containing only two pulleys. However, a two pulley set wouldhave to have larger diameter pulleys.

2. Cables 44' and 46' are each slung about pulley sets having only twopulleys each, i.e. pulleys 122 and 124, as opposed to the three pulleysets illustrated in FIG. 2.

FIGS. 10 through 21 illustrate another apparatus of the presentinvention for driving a wheelchair 200 having a pair of propulsionwheels 212 which are attached to the frame of wheelchair 200. Theapparatus (one of which is located on each side of the wheelchair)includes a first drive sprocket 214 for driving a propulsion wheel 212which is attached to and axially aligned with sprocket 214 by an axle216.

A second drive sprocket 218 is also provided as well as a first drivechain 220 which is slung about the pair of first and second drivesprockets 214, 218. In addition, a third drive sprocket 222 is providedwhich is axially aligned and rigidly attached to the second drivesprocket 218 by an axle 223 (See FIG. 13). A fourth drive sprocket 224is also provided as well as a second drive chain 226 which is slungabout the pair of third and fourth drive sprockets 222, 224.

The apparatus further includes a first handle 228 for driving chain 226in a clockwise direction and propelling the wheelchair forward. Handle228 is rigidly attached to a first base plate 230 by a connecting member232 (see FIG. 16). The apparatus also includes a second handle 234 fordriving chain 226 in the opposite direction (i.e. the wheelchair inreverse) which is connected to a second base plate 236 as bestillustrated in FIG. 17 by a connecting member 238.

The first and second base plates 230, 236 are connected together asillustrated in FIGS. 16 and 17 (see also FIG. 13) by a pair ofthree-link chain segments identified respectively by numerals 240 and242. As illustrated, each link of each three link chain is identified bythe letters (a), (b) and (c). It will be appreciated that first (orlower) base plate 230 is connected to the second (or upper) base plate236 by pivotally attaching the outer ends of links 240(a) and 242(c) tolower base plate 230 with pins 244 and 246, respectively, and bypivotally attaching the outer ends of links 240(c) and 242(a) to uppersecond base plate 236 with pins 248 and 250 respectively. Those skilledin the art will appreciate that by connecting base plates 230 and 236together in this manner, base plates 230 and 236 are moveable relativeto each other in a direction parallel to the linear paths of travel madeby drive chain 226.

It will also be appreciated from FIGS. 16 and 17 that base plates 230,236 direction of movement is maintained in alignment with chain 226'slinear paths of travel by attaching base plates 230 and 236 to ballbearing track means 252 which, in turn, are rigidly attached to ahousing 253 of the apparatus which is rigidly attached to thewheelchair's frame (not numbered). As illustrated in FIGS. 16 and 17,four track means 252 are provided, two of which are attached to eachbase plate to control its movement so that it only moves linearly in thedirection of the drive chain's linear paths of travel.

Returning now to FIG. 13, it will be appreciated that base plate 230 isprovided with a pair of chain backstops 254 and 256, which prevent chain226 from being pushed by three-link chain segments 240 and 242 when itis engaged thereby as is explained in more detail below.

The cooperation of the drive apparatus' components will now be describedto explain how the wheelchair is propelled in a forward direction bymaking downstrokes and upstrokes with handles 228 and in a reversedirection by doing the same with handles 234. FIG. 13 illustrates theposition of the drive apparatus' components when the wheelchair occupantis making a downstroke with the forward pair of handles 228. Asillustrated, the pivotal connection 260 of links 240(a) and 240(b) isengaging chain 226 by pressing a link 227 of the driven chain up againstbackstop 254. Pivotal connection 260 is also referred to herein as thefollowing end of center link 240(b) because it follows center link240(b)'s other pivotal connection 262 (referred to as the leading end262) when the chain is moving clockwise. Pivotal connection or followingend 260 engages link 227 by impacting up against the concave edges ofthe link which, as previously mentioned, is prevented from movinginwardly by backstop 254. Thus, it will be appreciated that end 260 inessence grabs a link 227 of chain 226 to drive it in a clockwisedirection as illustrated in FIG. 13. The clockwise movement of chain 226drives sprocket 218 attached to axle 223 which in turn drives sprocket214 and wheel 212, thereby propelling the wheelchair.

It will also be appreciated from an inspection of FIG. 13 that while end260 is engaging link 227, three link chain segment 242 is not engagingor making contact with chain 226. Chain segment 242 is prevented fromcontacting the drive chain due to the inertia of handle 234 and attachedbase plate 236 which in essence pulls chain link segment 242 out ofengagement with the chain by pulling against pin 250 in a directionopposing handle 228's direction of movement. As will be recalled, theother end of three link chain segment 242 is prevented from beingsimilarly pulled since it is attached to the lower base plate 230 by pin246 which is connected to forward handle 228.

At the instant the wheelchair occupant completes a downward stroke andbegins making an upstroke with handle 228, chain link segments 240 and242 reverse positions and thereby pass through their neutral positionsillustrated in FIG. 21 to their positions illustrated in FIG. 20 whereinit will be appreciated that end 270 of chain link segment 242 isengaging a link 271 of chain 226. Those skilled in the art willappreciate that it is again the inertia of upper base plate 236connected to rear handle 234 which pushes end 270 of chain link segment242 into engagement with a link 271 and pulls end 260 of chain segment240 out of engagement with chain 226. This happens because the inertiaof upper base plate 236 in essence pulls pin 248 in a downward directionopposing the direction of the upstroke (as indicated by the arrow inFIG. 20) thereby pulling chain link segment 240 out of engagement withchain 226, as such permitting the chain to travel in a clockwisedirection between backstop 254 and chain link segment 240.

When a wheelchair occupant reaches the end of an upstroke and beginsmaking a downstroke with handles 234, chain link segments 240 and 242again reverse position (and thereby assume the position illustrated inFIG. 13) to continue driving chain 226 in a clockwise direction.

If the wheelchair occupant lets go of handles 228, the chain linksegments will release chain 226 and assume the position illustrated inFIG. 21. In this position, the wheelchair may be pushed or propelledconventionally by grabbing rear wheels 212 or by a third party graspinghandles 213 of the wheelchair.

To propel the wheelchair in reverse, the wheelchair occupant simplygrabs handles 234 and begins making downstrokes and upstrokes therewith.It will be appreciated that the three-link chain engaging segments 240and 242 now propel drive chain 226 in a counter-clockwise direction. Itwill further be appreciated that the operation of the chain linksegments is identical to that previously described for driving the chainclockwise with the exception that lower base plate 230 and attachedhandle 228 now provide the inertia for moving or pulling the three-linkchain segments 240 and 242 into and out of engagement with drive chain226. It will further be appreciated that FIG. 13 illustrates theposition of three-link chain segments 240 and 242 when the wheelchairoccupant is making an upstroke with reverse handles 234 with theexception, however, that end 262 of center link 240(b) will engage alink 271 of drive chain 226 instead of the center link's end 960. Aspreviously mentioned, it is always the following end which engages alink of the drive chain. Since chain 226 is now moving in the reverse,i.e. counterclockwise direction, the following end is end 262. Thus,FIG. 20 illustrates the position of three-link chain segments 240 and242 when the wheelchair occupant is making a downstroke with reversehandles 234 with the exception, however, that end 272 of link 242(b)will engage a link 271 of drive chain 226 instead of the illustrated end270. As will be appreciated, end 272 is the following end when chain 226is moving in a counterclockwise direction.

As also illustrated, center links 240(b) and 242(b) have a length whichis about 11/2 times the length of a link 227 of drive chain 226. Inaccordance with an important aspect of the invention, center links240(b) and 242(b) are provided with a length which is greater than thelength of a link 227 of the drive chain so that only the following endof the center links engages a link of the drive chain. If center links240(b) and 242(b) had the same length as a link of the drive chain, boththe leading and following ends of the center link could engage andpossibly stick to drive chain 226, as such possibly preventing thethree-link chain segments from releasing the drive chain at the end of astroke. By using center links which are slightly longer than those of achain link 227 (preferably 11/2 times the length), jamming or failure torelease drive chain 226 should not occur.

As illustrated in FIG. 11, the drive apparatus of wheelchair 200 canalso be pivoted upwardly about shaft 223 from about its 45° angledepicted in FIG. 11 to a horizontal position as depicted in FIG. 14 anddepicted in phantom in FIG. 11. The ability to pivot the apparatusallows the wheelchair occupant to position the apparatus at acomfortable angle.

FIGS. 22 through 26 illustrate another drive apparatus of the presentinvention for driving a bicycle 300. This embodiment is similar to theprevious embodiment for driving a bicycle in that this embodiment alsouses a chain engaging means for releasably engaging a second drive chainto continuously drive the second drive chain as the operator pedals thebicycle which, in turn, continuously drives a first drive chain topropel the bicycle's rear wheel and thus the bicycle. As with bicycle100, this embodiment has a first drive sprocket 310 which is attached toand axially aligned with the bicycle's propulsion wheel 312 and whichdrives the bicycle's propulsion wheel when it is driven. A second drivesprocket 314 is also provided as well as a first drive chain 316 whichis slung about sprockets 310, 314. In addition, two drive assemblies(not numbered) are provided for being driven by a bicyclist pedallingthe bicycle with its right and left pedals 324, 326, to which the driveassemblies are respectively attached. Each drive assembly includes apair of third and fourth drive sprockets 318, 320 about which a seconddrive chain 322 is slung. As seen in FIG. 24, the third drive sprockets318 of each drive assembly are axially aligned with each other and withsecond drive sprocket 314 by an axle 328. Sprockets 318 and sprocket 314are also fixedly attached to axle 328 and connected to each other sothat if right sprocket 318 is driven, sprocket 314 and the other, i.e.left sprocket 318 of the other drive assembly will also rotate.

In accordance with an important aspect of the present invention, eachpedal 324, 326 is connected to an elongated slot defining chain engagingmeans or member 330 which drives its respective second drive chain 322by engaging a drive pin 334 attached to the pivotal connectionconnecting two links of drive chain 322. As best illustrated in FIGS. 25and 26, drive pin 334 extends outwardly from drive chain 322 a distanceso that it extends through an elongated slot 332 defined by slotdefining chain engaging means 330. Each slot defining chain engagingmember is also rigidly attached to its respective pedal 324, 326 so thatit is capable of driving its respective drive chain 322 via itsrespective drive pin 334 as the bicycle is pedaled with pedals 324, 326.

As best illustrated in FIG. 23, each slot has a length which is greaterthan or equal to the outside diameter of the larger of the third orfourth drive sprockets. In the illustrated embodiment, the third andfourth drive sprockets have the same diameter. Nonetheless, it isimportant that slot 332 have a width which is greater than eithersprocket (if it is desired to use differently sized sprockets) so thatdrive pin 334 received in the slot can slide from one end 336 of theslot to its other end 338 and thereby rotate around the larger sprocket.

FIGS. 25 and 26 also illustrate that the right and left sides (notnumbered) of each slot defining chain engaging member 330 are receivedwithin tracks 340 of the drive assembly's housing 342. Tracks 340 serveto maintain member 330's ends in alignment with the linear portions ofthe drive chain's path of travel. Track 340 is also preferably providedwith bearing means (not shown) for reducing friction between the trackand chain engaging member and for maintaining the generally horizontalposition of the chain engaging member as downward and upward strokes aremade with the pedal to which it is attached.

To propel the bicycle with the illustrated drive apparatus, onepreferably begins by making a downstroke with either pedal 324 or 326.In a real world situation, one would begin making a downstroke with thepedal in a position near the top (or beginning) of its stroke which asillustrated in FIG. 26 would be pedal 326. As will be appreciated, whenmaking the downstroke, drive pin 334 will be positioned against (or atleast near) the forward end 336, (i.e. right end as depicted in FIG. 26)of slot 332. The power generated by the bicyclist making the downstrokewill be transmitted from the pedal and attached slot defining chainengaging member 330 to drive pin 334 which in turn will drive the seconddrive chain 322. At the end of a downstroke, the drive pin will slide inslot 332 away from its forward end 336 to its rearward end 338, as itfollows the arc made by the drive chain as it travels across thirdsprocket 318. When the bicyclist makes a power generating downstrokewith the other pedal, drive pin 334 will carry the slot defining chainengaging member and attached pedal to its top position so that thebicyclist can begin making another power generating downstroke.

It will be appreciated that the right and left pedals cooperate in thismanner to return each pedal to its top position by being positionedone-half of a cycle out of phase with each other. (See FIG. 24) As such,when the right pedal reaches its lowermost position at the end of adownstroke, the left pedal will be at its uppermost position and inposition to begin making a power generating downstroke therewith. (Itwill also be appreciated that the respective chain engaging members 330and drive pins received thereby are similarly out of phase with eachother.)

While it is generally anticipated that most bicyclists will only drivethe apparatus by making power generating downstrokes, those skilled inthe art will appreciate that it is possible to generate additional powerby driving the bicycle with an upstroke as well. This is easilyaccomplished with the drive apparatus of the present invention by simplysecuring the bicyclist's foot to the pedal in some manner. It isanticipated that professional bicycle racers will utilize the driveapparatus in this manner which readily lends itself to such use due toits linear nature.

While the general operation of the drive apparatus for driving bicycle300 has been described, it is important to also note that the slotdefining chain engaging member must move linearly (i.e. in a straightline located between the centers of the third and fourth sprockets) adistance equal to the lengthwise diameter of the drive chain's path oftravel. If the chain engaging member, (and for that matter the pedal towhich it is attached) does not move this required distance, drive pin334 will not be able to slide in slot 332 from its forward end 336 toits rearward end 338, or vice versa. Thus, the drive chain will not beable to make a complete revolution, or for that matter, even one-half ofa revolution. It is also important that the chain engaging member notmove a distance greater than the lengthwise diameter of the drivechain's path of travel. If it could, it could pull the drive chain offsprockets 318, 320. Such excessive movement is prevented in theillustrated embodiment, by the top and bottom portions of housing 342.While such limited movement may appear to be a problem, those skilled inthe relevant art will appreciate that the drive apparatus can be easilyadjusted to accommodate bicyclist who make long (or short) strokesbecause the distance between the third and fourth sprockets can beeasily adjusted. While no means for adjusting this distance is not shownor described, those skilled in the mechanical arts will have nodifficulty devising such a device. Of course, if the distance betweenthe third and fourth sprockets is changed, the length of the drive chainwill have to be changed accordingly.

FIGS. 27 through 29 illustrate a drive apparatus 400 of the presentinvention for driving the drive shaft 410 of a motor vehicle. As withthe other embodiments, this apparatus transmits or converts powergenerated linearly, i.e. in this case, power generated by a stroke of apiston head into rotary power for purposes of rotating drive shaft 410.

As illustrated, drive shaft 410 is attached to a sprocket 412 which isaxially aligned with drive shaft 410. Sprocket 412 is driven by a drivechain 414 which is slung about four pulleys which are identified hereinas first pair of pulleys 416, 418 and second pair of pulleys 420, 422.While pulleys are illustrated, guide sprockets could also be utilized.

As those skilled in the art will appreciate, to engage and drivesprocket 412, the distance between the centers of each pair of pulleys416, 418 and 420, 422 must be less than the diameter of sprocket 412.Thus, the diameters of each pulley must be less than one-half thediameter of sprocket 412. In addition, sprocket 412 must be located andcentered between the two pairs of pulleys as illustrated. Moreover,straight lines drawn through the centers of each pair of pulleys shouldalso be parallel to each other for reasons which will become apparentfrom the following description.

Returning now to previously mentioned drive chain 414, it can be seen inFIGS. 27 and 28 that drive chain 414 is provided with three drive pins424(a), (b) and (c) which are spaced equally from each other, i.e. thedistances between each drive pin as measured along the chain are equal.FIG. 29 illustrates that the drive pins project outwardly a certaindistance from both sides of drive chain 414.

FIGS. 27 and 28 also illustrate drive apparatus 400 is provided with apair of axially aligned piston heads 430 which are connected by opposingconnecting rods 432, 433.

In accordance with an important aspect of this embodiment of theinvention, each opposing connecting rod 432, 433 defines an opposingnotch 434 and groove 436. As illustrated in FIG. 29, each notch 434extends across the entire width of each connecting rod 432, 433. Eachnotch is also sized and configured to receive drive pins 424 attached todrive chain 414. Each drive pin also has a length which is slightlygreater than the width of the connecting rod so that the opposing endsof each drive pin project slightly out from the sides of each connectingrod. In addition, each groove defined by the connecting rod is sized andconfigured to receive drive chain 414 so that the drive chain can travelthrough the groove. It is also important as illustrated in FIG. 28 thateach groove communicate (i.e. open into) its respective notch 434 andextend along the length of the connecting rod a distance which is atleast equal to the length of the piston's stroke. The importance of thiswill be appreciated shortly and is described in more detail below. Inaddition, a factor which should be considered in the design of a driveapparatus 410 is the length of the pistons' stroke which will always beequal to one-half the distance between two drive pins.

Returning to the Figures, it will be seen that the connected pair ofpiston heads 430 and previously described drive assembly components arehoused within a cylindrical chamber 440. The chamber is similar to thatfound in most internal combustion engines with the exception that thecylinder is provided with intake and exhaust ports 442, 444respectively, and spark plugs 446 at both of its ends 448 and 450.Accordingly, it will be appreciated that the connected pair of pistonheads 430 can be driven in a reciprocating manner by properly timing thefiring of the spark plugs located in ends 448 and 450 of the chamber.The timing and firing of the spark plugs can be done in any conventionalmanner known to those skilled in the relevant art.

The operation of apparatus 400 to drive chain 414 which in turn drivesdrive shaft 410 is as follows. FIG. 27 illustrates the connected pair ofpiston heads 430 making an upstroke wherein drive pin 424(a) is receivedwithin the notch 434 of connecting rod 433. As will be appreciated,connecting rod 433 carries drive pin 424(a) upwardly (thereby drivingchain 414) until the end of the upstroke is reached, the end of which isillustrated in FIG. 28. At this point, it will be appreciated that drivepin 424(a) is in the process of exiting notch 434 of connecting rod 433.As this is happening, however, it will also be appreciated that drivepin 424(b) is entering notch 434 of connecting rod 432 to continuedriving chain 414. When piston heads 430 begin to make their downstroke,i.e. when spark plug 446 located in end 448 is fired, drive pin 424(b)will be completely received within notch 434 of connecting rod 432 andwill thereby be in position to continue driving chain 414 in acounter-clockwise direction. When piston heads 430 complete theirdownstroke, drive pin 424(b) will exit the lower end of groove 436 ofconnecting rod 432. At this point, drive pin 434(c) will enter notch 434of connecting rod 433 which will carry it upwardly as previouslydescribed during the piston heads upstroke as illustrated in FIG. 27. Inview of the above, it will be appreciated that chain 414 will be drivencontinuously which in turn will drive sprocket 412 continuously and, assuch, rotate drive shaft 410 continuously.

As with the other embodiments, those skilled in the art will appreciatethat the present invention converts substantially all of the linearpower generated by the linear movement of the piston heads to rotarymotion, thereby providing a system which is much more efficient thanthat provided by conventional drive apparatus for driving a vehicle'sdrive shaft. Those skilled in the fuels art will also appreciate thatunlike conventional gasoline engines using conventional pistontechnology which require relatively high octane fuel, the duel headedpiston apparatus of the present invention can operate quite efficientlyon lower octane fuels.

The invention has been described in detail with reference to particularembodiments thereof, but it will be understood that various othermodifications can be effected within the spirit and scope of thisinvention.

What is claimed:
 1. An apparatus for continuously transmitting energy toor from an axle, shaft and the like, said apparatus comprising:firstsprocket/pulley means axially aligned with and connected to an axle;flexible ratch means for engaging said sprocket/pulley means; andcooperating first and second energy transmitting ratch engaging meansfor releasably engaging said flexible ratch means to continuously drivesaid sprocket/pulley means which, in turn, continuously drives the axlewhen energy is transmitted by said first and second ratch engaging meansto said flexible ratch means.
 2. An apparatus as claimed in claim 1further comprising:handle/pedal means attached to said cooperating firstand second ratch energy transmitting engaging means for powering by anindividual to enable an individual to drive said first sprocket/pulleymeans which, in turn, drives said axle.
 3. Am apparatus as claimed inclaim 1 wherein said flexible ratch means includes a member selectedfrom the group of flexible chain, flexible belt and flexible cable. 4.An apparatus as claimed in claim 1 wherein said flexible ratch means isslung about said first sprocket/pulley means and a secondsprocket/pulley means, and wherein said first ratch engaging meansengages said flexible ratch means when said first ratch engaging meansis moved in a first linear direction between said first and secondsprocket/pulley means and wherein it releases said flexible ratch meanswhen it is moved in a second linear direction opposing the firstdirection, said second ratch engaging means engaging said flexible ratchmeans when said second ratch engaging means is moved in the seconddirection and releasing said flexible ratch means when it is moved inthe first direction, said first and second ratch engaging meanscooperating so that one of said first and second ratch engaging meansengages said flexible ratch means as the other of said first and secondratch engaging means releases said flexible ratch means.
 5. An apparatusas claimed in claim 4 further comprising a wheelchair having a pair ofpropulsion wheels driven by a pair of said axles.
 6. An apparatus asclaimed in claim 4 further comprising a bicycle having a wheel driven bysaid axle.
 7. An apparatus as claimed in claim 1 furthercomprising:piston means attached to said cooperating first and secondenergy transmitting ratch engaging means for receiving and transmittingenergy to enable said cooperating first and second energy transmittingratch engaging means to releasably engage said flexible ratch means tocontinuously drive said sprocket/pulley means which, in turn,continuously drives the axle.
 8. An apparatus as claimed in claim 7wherein said piston means is housed within a cylindrical chamber of aninternal combustion engine for permitting reciprocal motion of saidpiston means within said cylindrical chamber.
 9. An apparatus as claimedin claim 8 wherein said axle is connected to a motor which drives saidaxle which in turn rotates said sprocket/pulley means to drive saidflexible ratch means which in turn is releasably engaged by saidcooperating first and second ratch engaging energy transmitting meanswhich transmits energy from said motor to said piston means to pumpfluid through said cylinderical chamber.
 10. An apparatus as claimed inclaim 8 wherein said piston means includes a pair of axially alignedpiston heads connected by opposing connecting rods, said opposingconnecting rods defining said cooperating first and second energytransmitting ratch engaging means.
 11. An apparatus as claimed in claim1 further comprising a pair of axially aligned piston heads connected byopposing connecting rods wherein said connected pair of axially alignedpiston heads is housed within a cylindrical chamber permittingreciprocating motion of the axially aligned pair of piston heads whenthe piston heads are reciprocally driven by controlled explosions offuel occurring in the chamber between the ends of the cylindricalchamber and the piston heads and wherein said flexible ratch meansincludes an endless drive chain slung about first and second pairs ofsecond sprocket/pulley means, all of which have a diameter which is lessthan half the diameter of said first sprocket/pulley means, the centersof said first pair of second sprocket/pulley means being located adistance apart from one another which is less than the diameter of saidfirst sprocket/pulley means, the centers of said second pair of secondsprocket/pulley means also being located a distance apart from oneanother which is less than the diameter of said first sprocket/pulleymeans, said first and second pairs of second sprocket/pulley meansfurther being oriented so that a straight line drawn between the centersof the first pair is parallel to a straight line drawn between thecenters of the second pair, said first sprocket/pulley means furtherbeing centered between said first and second pairs of said secondsprocket pulley means such that said first sprocket/pulley means isengaged by said drive chain on opposite sides thereof, and wherein saiddrive chain means includes three equidistant drive pin means extendingoutwardly from a link of said drive chain for cooperating with saidchain engaging means to transmit force to said drive chain to drive saidchain in one direction, andwherein said cooperating first and secondratch engaging energy transmitting means include opposing groove/notchmeans defined by said opposing pair of connecting rods for receivingsaid drive, chain and drive pin means wherein said notch is sized andconfigured to receive said drive pin means and said groove is sized andconfigured to receive said drive chain for movement therethrough, saiddrive pin means being positioned on said drive chain and cooperatingwith said opposing notches of said connecting rods so that one of saiddrive pin means is received by one of said opposing notches as theimmediately following drive pin means exits the opposing notch means atthe end/beginning of each power stroke made by said connected pair ofpiston heads.
 12. A method for continuously driving an axle, shaft andthe like, said method comprising the steps of:providing an apparatusincluding:first sprocket/pulley means axially aligned with and connectedto an axle; flexible ratch means for engaging and driving said firstsprocket/pulley means; cooperating first and second ratch engaging meansfor releasably engaging the flexible ratch means to continuously drivethe sprocket pulley means which, in turn, continuously drives the axle;moving the first and second ratch engaging means in the direction of thelinear paths of the flexible ratch means so that the first ratchengaging means engages and drives the flexible ratch means which rotatesthe sprocket/pulley means which, in turn, drives the axle; and reversingthe first ratch engaging means' direction of movement so that the firstratch engaging means releases the flexible ratch means as the secondratch engaging means engages the flexible ratch means to continuouslyrotate the sprocket/pulley means which, in turn, continuously drives theaxle.